This disclosure relates to information management.
In some examples, when a user sends a query to a server to request information, the server returns results in response to the query and sponsored content (e.g., advertisements, or ads) that is relevant to the query. The server may automatically select ads using a two-step process. In the first step, a set of candidate ads are selected from a large pool of ads. For keyword-based ads, the candidate ads can be selected based on matching the query with a set of keywords associated with each ad. For keyword-less ads, the candidate ads can be selected based on matching features associated with the query and ads. For example, the features can include categorizations of the query and the ad, a relevance score between the query and creative text of the ad, and features derived from a landing page of the ad. In the second step, the candidate ads are ranked and the best N (N being an integer) ads are selected. The best N ads are served to the user.